Application of PZT thick-films on adjusting purposes in micro-optical systems

A PZT thick-film is printed on an Al2O3-Substrate, generating a cantilever monomorph. A task of positioning with two degrees of freedom is successfully fulfilled. It is realized by, two parallel arranged cantilevers that are mechanically combined with a bar with solid hinges. The solid hinges allow flexibility for different amounts of bending of the two cantilevers, while the bar permits a stiff support for a lens. As the bar underlies very small torsion there is no stress induced change in the index of refraction of the lens. Different combinations of hinges are simulated and practically tested. In the presented work, a lens is successfully positioned in front of a laser diode. The loss of the coupling efficiency due to the shrinking of the adhesive joint can be scaled down. The paper presents the theoretical work including the report on analytic and FEM simulation of both deflection and stress. The practical validation is also presented. A simple sensor system is used to find an optimized position of the lens in front of the diode. This position is automatically held over a long period of time. With the fabrication of the actuator using thick-film printing and laser cutting a low cost device is built.